Glossary of Terms
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Contaminants
Water is often referred to as the universal solvent. This is because it likes to dissolve almost everything that it comes into contact with. We collectively refer to these particles as contaminants. Contaminants are anything except H2O present in a sample of water. These are not always harmful and come mineral contaminants can actually be good for you! any physical, chemical, biological or radiological substance or matter in water.
GPG and Mg/L
There are a few ways that we can use to measure contaminants. One way is with milligrams per litter. This is a concentration unit typically used to measure hardness and chlorine levels in water.
Another unit of measurement is called PPM or Parts Per Million. This unit is typically used to measure concentrations of Iron in a water sample.
Milligrams per liter and Parts Per Million are essentially the same in water. This means that is you have 3 Mg/L of Iron in your water, you also have 3 PPM of iron in your water.
Another way to measure hardness is with GPG or grains per gallon. This is what we typically use in our water softeners. It is easy to convert from Mg/L of hardness to GPG. You will simply divide by 17.1. For example, if your city water supply says that there is 154 Mg/L of hardness in the water, you would divide by 17.1 to convert that value to 9 gpg hardness. You always need to know your supply water’s hardness in GPG so that your can correctly program the softener to this value.
A unit of water hardness defined as 1 grain of hardness dissolved in 1 US gallon of water.
Grains
I like to imagine “Grains” of hardness as “grains” or rice. If you were told that the water supply has 15 gpg total hardness, you can think of each gallon of water containing 5 grains of rice in it. This visualization helps when looking at softener capacity. All softener have a rated capacity listed in “grains”. What this means is that that model softener can take out a total of that many “grains of rice” before it has to trigger a recharge. For example, if you have a water softener that has 30,000 grains of softening capacity, it can take out 30,000 grains of hardness before regeneration. Lets further say that the supply water contains 10 grains per gallon of hardness. If you divide these numbers, you can see that that model softener would be able to treat 3,000 gallons of water at that hardness before needing to recharge. This is why water softener meter water usage. They use the water hardness and usage to calculate when a recharge is needed.
Hardness (Calcium, Magnesium)
Now that we have talked about how to measure contaminants in water, lets take a deeper look at what exactly these contaminants are. Our main contaminant in water is Hardness. Hard water is any water sample that contains Calcium and Magnesium ions. These minerals tend to create what is known as scale buildup. This can be seen as white spots on dishes, white scaly buildup on fixtures and heating elements and can even result in high levels of soap and detergent use. This contaminant typically does not cause adverse health effects, but can greatly decrease the aesthetics of a water supply. Hard water comes from ground water contact with rocks such as limestone. This is why certain regions of the US have harder water than others. Water hardness is also typically higher in private well water sources compared to public water sources. It is important to know your incoming water hardness concentration in GPG when selecting and programing a water softener.
Hardness Test Strips
Hardness test strips are one common and easy way to test for water hardness. These strips can be held under a water faucet for a few seconds then the strip will change colors. Customers can compare the color against a chart to find out what their water hardness is. If the customer is on a public water supply, they can also contact their local water supply company and ask them what the water hardness is.
An electronic TDS meter cannot be used to measure water hardness. We will talk about why in a minute.
Iron (Ferrous, Ferric)
Another common contaminant in water supplies is Iron. Iron is a natural mineral found in groundwater that can have significant aesthetic effects on a water supply. Elevated levels of Iron can result in red or orange staining, even if the water appears clear from the faucet. There are two main types of Iron found in water.
The first type of Iron is call Ferrous or clear water iron. This is iron that is completely dissolved in the water and has no orange color at all. Ferrous Iron can be reduced with a water softener up to the specified levels for each unit. Ferrous iron can be converted to the other form of iron then exposed to air or another oxidant.
The other form of Iron is called Ferric or red water iron. This is Iron that can been oxidized into tiny suspended particles in the water supply. Once in this form the Iron will have a color that ranges from pale yellow to deep red. Ferric iron cannot be removed by a water softener, but It can be reduced with a pre-filter before the softener.
TDS
TDS or Total Dissolved Solids is the measurement of ALL the minerals and contaminants in the water. It does not differentiate between contaminants. This measurement is usually tested with a little electronic device that calculated the conductivity of electricity through the water. This measurement is highly valuable when evaluating the function of an RO, or Reverse Osmosis, system but is effectively useless when evaluating the performance of a water softener. This is because a softener uses a process known as Ion Exchange to soften the water.
Ion Exchange
Ion Exchange is a process in which a media is used to exchange one ion, or mineral, for another. With a water softener the media will remove hardness minerals, Calcium and Magnesium, and exchange them with more acceptable minerals such as Sodium or Potassium. The water will have the same total number of contaminants, TDS, but they will just be different contaminants. Sodium and Potassium do not create scale buildup like hard water does.
Recharge
Over time, the media will slowly loose its capacity to soften the water. This is why it must go through a regeneration, or recharge process. During this process the softener creates a very salty solution, called brine, that is slowly flowed over the media. This recharges the medias surface with sodium so that it can continue to soften the water.
Media (Resin)
The media used inside softener is called resin. This is a plastic polymer media that appears as tiny amber colored beads. This resin is a strong end effective ion exchange media. It can take out approximately 30,000 grains of hardness per cubic foot or resin. This resin can be fouled with continued exposure to oxidants, such as chlorine, or ferric iron.
Tank Style (cabinet, two-tank)
Water softeners come in two basic configurations, cabinet or two-tank. Two tank systems have a separate resin tank and brine tank. The cabinet units place the resin tank inside the brine tank area. This saves space at installation.
Salt (Sodium, Potassium)
Water softeners must be supplied with salt. This salt is only used during the regeneration process to create the brine needed to recharge the resin. Most customers are accustomed to using regular Sodium Chloride salt. This can be found in pellet or crystal forms. With this salt, hardness minerals are exchanged for Sodium in the softening process. Customers can also use Potassium Chloride salt. This is a specialty salt for customers with certain health restrictions to Sodium. Instead of adding Sodium to the softened water, this salt will add Potassium.
Chlorine
Chlorine is a contaminant commonly found in public water supplies. It is used as a disinfectant to protect water supplies and ensure the safety of the water supplied to the public. It is not naturally found in private well water supplies unless the customer has installed chlorine feed disinfection equipment. Chlorine can cause an objectionable taste and odor to the water. It will also slowly oxidize, or breakdown, softening resin over time.
Carbon Filtration
Activated Carbon is a media that is used to reduce Chlorine levels in water supplies. This can be used as a whole home water filter, in conjunction with softening in a hybrid softener, or just for the drinking water in an under-sink system. Carbon filters are used to reduce the chlorine levels by about 50% in most whole-home units. Specific product claims can be found in the manuals of each unit.
Water Supplies (city, well)
There are two general supplies of water that most home owners are connected to. Public water supplies are your city or municipal sources. These supplies must meet regulated standards set by governing agencies. These supplies tend to have elevated chlorine levels, moderate hardness, and very low levels or Iron and sediment. Private water supplies typically come from the homeowner’s privately owned wells. There are no government regulations on the water supply quality in private wells. These supplies typically have elevated levels of hardness, Iron, and TDS. They can sometimes have high levels of sediment, but typically have no Chlorine.
Drinking Water Filtration
Some customers require specific filtration equipment just for their drinking water supplies. This equipment is much smaller and does not treat all the water supplied to the house. These units use disposable filter cartridges that must be replaced regularly.
Configuration
There are two filter configurations. Inline filters and narrow filters that have an inlet water connection on one side and an outlet on the other. Water flows straight through the inside of this filter and out the other side. The entire filter and housing is replaced on a regular basis. Other units use a manifold type system. In this configuration there is a solid manifold that remains connected to the incoming and outgoing water lines. Disposable filter cartridges then attach to this permanent manifold. Only the filter cartridges must be replaced on a regular basis.
Stage
Each filter represent a stage of filtration in the unit. For example, a dual stage unit would consist of two filters. A 3-stage unit would consist of three filters.
RO
Reverse Osmosis, RO, is a special type of drinking water filtration that utilizes Membrane Separation technology. These units require a product water storage tank as well as wastewater disposal. This means that as an RO produces good product water, it must also flow some water down the drain as waste.
Whole Home Filtration
Some customers will require specific filtration for the entire home. This is typically installed at the resident supply connection before the softener or any drinking water filtration. These filters are used for other contaminants such as sediment, ferric iron, Chlorine and chloramine, Acid or low pH water. There are even specialty filters that can be used to reduce scale without softening.
Sump Filters
Sump style filters have a filter housing and internal filter cartridge. The cartridge indicated what type of filtration will be performed. To regularly change out the disposable filter inserts, you have to open up the housing.
Tank filters
Tank filters have a large mineral tank with media and a valve control head. The mineral tank will contain whatever type of media is required for specific filtration needs. The valve on top is used to control the water flow through the mineral tank. The benefit of this control is that you can set regular backwash or clean cycles to reduce the accumulation of contaminants in the media bed.
Anti Scale
Anti Scale units use a specialty media to prevent scale buildup within a residence. These unit is not soften the water. Instead the tie up hardness minerals to reduce the effects of scale buildup on surfaces and heating elements.